Method setDetailFromDistance

Engine/source/ts/tsShapeInstance.cpp:626–703

}

S32 TSShapeInstance::setDetailFromDistance( const SceneRenderState *state, F32 scaledDistance )
{
   PROFILE_SCOPE( TSShapeInstance_setDetailFromDistance );

   // For debugging/metrics.
   smLastScaledDistance = scaledDistance;

   // Shortcut if the distance is really close or negative.
   if ( scaledDistance <= 0.0f )
   {
      mShape->mDetailLevelLookup[0].get( mCurrentDetailLevel, mCurrentIntraDetailLevel );
      return mCurrentDetailLevel;
   }

   // The pixel scale is used the linearly scale the lod
   // selection based on the viewport size.
   //
   // The original calculation from TGEA was...
   //
   // pixelScale = viewport.extent.x * 1.6f / 640.0f;
   //
   // Since we now work on the viewport height, assuming
   // 4:3 aspect ratio, we've changed the reference value
   // to 300 to be more compatible with legacy shapes.
   //
   const F32 pixelScale = (state->getViewport().extent.x / state->getViewport().extent.y)*2;

   // This is legacy DTS support for older "multires" based
   // meshes.  The original crossbow weapon uses this.
   //
   // If we have more than one detail level and the maxError
   // is non-negative then we do some sort of screen error 
   // metric for detail selection.
   //
   if ( mShape->mUseDetailFromScreenError )
   {
      // The pixel size of 1 meter at the input distance.
      F32 pixelRadius = state->projectRadius( scaledDistance, 1.0f ) * pixelScale;
      static const F32 smScreenError = 5.0f;
      return setDetailFromScreenError( smScreenError / pixelRadius );
   }

   // We're inlining SceneRenderState::projectRadius here to 
   // skip the unnessasary divide by zero protection.
   F32 pixelRadius = ( mShape->mRadius / scaledDistance ) * state->getWorldToScreenScale().y * pixelScale;
   F32 pixelSize = pixelRadius * smDetailAdjust;

   if ( pixelSize < smSmallestVisiblePixelSize ) {
      mCurrentDetailLevel = -1;
      return mCurrentDetailLevel;
   }

   if (  pixelSize > smSmallestVisiblePixelSize && 
         pixelSize <= mShape->mSmallestVisibleSize )
      pixelSize = mShape->mSmallestVisibleSize + 0.01f;

   // For debugging/metrics.
   smLastPixelSize = pixelSize;